1. International Research Center for Renewable Energy; State Key Laboratory of Multiphase Flow in Power Engineering; Xi'an Jiaotong University; Xi'an Shaanxi 710049 China
2. Department of Physics; Tamkang University; 151 Yingzhuan Rd. New Taipei City 25137 Taiwan
3. National Synchrotron Radiation Research Center; 101 Hsin-Ann Road Hsinchu Science Park Hsinchu 30076 Taiwan
4. Department of Chemistry; University of Wisconsin-Madison; Madison WI 53706 USA
5. Xi'an Jiaotong University Suzhou Academy; Suzhou Jiangsu 215123 China